Motor vehicle occupant impact protection arrangement

ABSTRACT

The present invention relates to a motor vehicle occupant impact protection arrangement ( 1 ). Said motor vehicle occupant impact protection arrangement ( 1 ) is comprising an airbag device ( 2 ) within a housing ( 3 ), an airbag device launch trigger ( 4 ), triggering the launching of said airbag device ( 2 ) upon a motor vehicle ( 7 ) impact, and a sheathing ( 5 ), such as a dashboard in an occupant compartment ( 6 ) of the motor vehicle ( 7 ), to which said housing ( 3 ) is connected, and behind which, in relation to the occupant, said airbag device ( 2 ) is located. Said sheathing ( 5 ) is having a mouth ( 8 ) through which said airbag device ( 2 ), guided by said housing ( 3 ), is launched into said occupant compartment ( 6 ). Said sheathing ( 5 ), after the launch of said airbag device ( 2 ), is adapted to essentially return to original state and to essentially close said mouth ( 8 ).

FIELD OF THE INVENTION

[0001] The present invention relates to a motor vehicle occupant impact protection arrangement. Said motor vehicle occupant impact protection arrangement comprising an airbag device within a housing, an airbag device launch trigger, triggering the launching of said airbag device upon a motor vehicle impact, and a sheathing, such as a dashboard in an occupant compartment of the motor vehicle, to which said housing is connected, and behind which, in relation to the occupant, said airbag device is located.

TECHNICAL BACKGROUND

[0002] Airbags of different types are present in many modern motor vehicles. They provide a means for protecting the occupants of the motor vehicle in the case of an impact and can for example be located under the dashboard, in the steering wheel, in the occupant seat or around a door opening. The different types are usually based on a similar technological idea of an inflatable airbag triggered upon an impact. The impact results in an explosive inflation of the airbag, which as a consequence breaks it way out through a path or housing and into the occupant compartment of the motor vehicle. In the occupant compartment, the occupant is due to the impact thrown towards the airbag that receives parts of the kinetic energy of the occupant and hence protects the occupant from being severely injured in a so called first impact. The airbag subsequently deflates and looses its ability to further protect the occupant.

[0003] However, the occupant may be injured during the first stage of launching the airbag since many airbags are located behind lids or other covers that are closed under normal use of the motor vehicle. The closure mechanism of the cover may consist of a closing latch or of a notch in the cover material, both of which need a specific amount of energy to open or to rupture, which the airbag provides during the launch. The airbag is adapted to build up such amount of energy within itself, as to overcome the initial opening energy needed to break loose into the occupant compartment before further inflation and intended use. Since the need of opening energy often is significant, the cover is flung open with considerable force and speed. This may in turn result in vehicle parts flying around in the occupant compartment and accidentally hitting and causing injury to the occupant.

[0004] A further inconvenience is that after the first impact there is, in many cases, a so called second impact caused by the large amount of kinetic energy involved in a motor vehicle accident. Since the airbag looses its protective ability after the deflation at the first impact, the occupant may instead, in a second impact, be thrown against a dashboard that now has open covers behind which the airbag formerly was located. The second impact may thus also result in occupant injury.

[0005] After an impact, not only exterior parts damaged in the impact need to be replaced or mended. Also interior parts, such as the dashboard behind which the airbag was formerly located, may be damaged since closing mechanisms of the lid or other covers may have been ruptured due to the inflation of the airbag. Repair work may be costly and spare parts such as dashboards are in general expensive. These costs are usually covered by insurance companies but transferred to the motor vehicle owners by increased insurance fees.

SUMMARY OF THE INVENTION

[0006] The object of the present invention is to provide a motor vehicle occupant impact protection arrangement that overcomes at least some of the above mentioned matters and present an improved impact protection arrangement.

[0007] According to the invention there is provided a motor vehicle occupant impact protection arrangement comprising an airbag device within a housing, an airbag device launch trigger, triggering the launching of said airbag device upon a motor vehicle impact, and a sheathing, such as a dashboard in an occupant compartment of the motor vehicle, to which said housing is connected, and behind which, in relation to the occupant, said airbag device is located. Said sheathing is having a mouth through which said airbag device, guided by said housing, is launched into said occupant compartment. Said sheathing is also, after the launch of said airbag device, adapted to essentially return to original state and to essentially close said mouth. This way, a motor vehicle occupant impact protection arrangement is provided, in which said sheathing, after an impact, subsequent launch and final deflation of said airbag device, is essentially returning to original position and state, and hence being kept intact for the occasion when there is a so called second impact. It is nor damaged in nay essential part by the opening and closing of said mouth, and hence not in need of being replaced. This way, the costs for insurance companies and the owners of motor vehicles are kept to a minimum.

[0008] In an embodiment of the invention said mouth can be an integrated part of and, or an aperture in said sheathing. This feature enables said airbag device to, upon launching, easily and without considerable force open up said mouth and give way for inflation of said airbag device in the occupant compartment. It also contributes to make the sheathing reusable, since there is not any ruptured opening mechanism of the mouth.

[0009] In a further embodiment said motor vehicle occupant impact protection arrangement, said housing is forming wedge-shaped sliding surfaces for said airbag device, said surfaces converging towards said mouth. This feature is adding the advantage that when the airbag device is inflating, the force of the inflated atmosphere within the airbag is urging the wedge-shaped housing and the aperture in the sheathing to open in a smoothly manner. Since the airbag device inflates in a continuous manner it does not build up an internal pressure leading to an explosive inflation within the occupant compartment like many airbags according to prior art. The sliding surfaces of the housing is adding to this advantage and reduces the friction between the airbag material and the housing.

[0010] Preferably, said housing, in the part connected to the sheathing, is adapted to form resilient jaws. The housing is more easily opened to release the airbag into the occupant compartment. This feature can be combined with a feature in which said housing in combination with said sheathing is forming a resilient part. Said part is suitably adapted to enable opening of said mouth against spring action and essentially closing of said mouth. The choice of material in and thickness of said sheathing in combination with the connection between the sheathing and the housing are of importance to the outcome of the resilience of the opening and closing of the mouth. Since the main purpose of the sheathing, apart from covering devices behind it, is to contribute to the protection of the occupant in case of an accident, it can continue to do so also after an impact. The sheathing is adapted to withstand the deformation caused by the opening of the mouth, and to resume the original state after the deflation of the airbag.

[0011] Suitably, said airbag device is comprising an inflatable airbag, which, upon triggering, is adapted to, against spring action, pressing said mouth to open, and to inflate in said occupant compartment.

[0012] A further advantage is provided by said airbag device, which is replaceable after fulfilling its purpose at a motor vehicle impact. This feature is adding to the cost efficiency of said arrangement. Said airbag device is replaceable by admission at a point on said sheathing essentially transversal to the direction of inflation of said airbag device. The airbag device behind a dashboard of a motor vehicle is preferably replaceable by admission at a point on said sheathing reachable from a motor vehicle door opening.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A currently preferred embodiment of the present invention will now be described in more detail, with reference to the accompanying drawings.

[0014]FIG. 1 is a side view of a motor vehicle with a motor vehicle occupant protection arrangement according to a preferred embodiment of the present invention.

[0015]FIG. 2, a-d is a cross-section of an airbag device during the steps of inflation and deflation of an airbag in a motor vehicle occupant impact protection arrangement, according to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0016] A first embodiment of the present invention related to a motor vehicle occupant protection arrangement will be described in more detail in the following, with reference to the accompanying drawings.

[0017] Referring now to FIG. 1, a motor vehicle occupant protection arrangement 1 is located in a motor vehicle 7 behind a dashboard 5 in the occupant compartment 6. The occupant protection arrangement 1 is triggered upon a motor vehicle 7 accident, such as an impact. The occupant protection arrangement 1 comprises an airbag 10, in an airbag device 2, which in turn is located in a housing 3. The housing 3 is adapted to hold the airbag device 2 and guide the airbag 10 out through a mouth 8 in the dashboard 5 into the occupant compartment 6. The housing 3 is forming sliding surfaces 9 for the guidance of the airbag 10. The mouth 8 in the dashboard 5 is an aperture in the dashboard, is such a way that the upper 12 and lower 13 parts of the mouth are kept in close contact with each other, but not locked together by any closing mechanism. The holding mechanism of the mouth is produced by the inherent stiffness of the dashboard 5 and of the resilience of the housing 3. The upper part of the mouth 12, i.e. the upper part of the aperture in the dashboard 5, is connected to the upper part of the housing 3. And likewise, the lower part of the mouth 13, i.e. the lower part of the dashboard 5, is connected to the lower part of the housing 3.

[0018]FIG. 1 is also showing a motor vehicle 7 in which an motor vehicle occupant impact protection arrangement according to a preferred embodiment of the present invention 1 is situated. On the side of the dashboard 5 facing a motor vehicle door opening 11, an airbag opening 14 is provided to make the airbag device 2 easily admissible for replacement after use. The airbag device 2 is replaced by transportation of it in the transversal direction of the direction of inflation of the airbag 10.

[0019] With reference now to FIGS. 2, a-d, the function of the occupant protection arrangement 1 will be described. In FIG. 2a the airbag device 2 is not yet launched and hence the mouth 8 is closed and the dashboard 5 is in its original state or position. In FIG. 2b the airbag device 2 is triggered and launching the airbag 10 through the housing 3 into the occupant compartment 6. The pressure within the airbag 10 is increased and leading to the inflation of the airbag 10. The inflation is in turn leading to the expansion of the airbag 10 and the expansion pressure on the housing 3 is urging the housing 3 and dashboard 5 to separate the upper and lower parts of the mouth, 12 and 13 respectively, opening the mouth 8. FIG. 2c the housing 3 and the mouth 7 in the dashboard 5 are fully opened and the airbag 10 is fully inflated. In FIG. 2d the airbag 10 is deflated and the housing 3 and the mouth 8 in the dashboard 5 have resumed their original state or position.

[0020] Although the present invention has been described in connection with particular embodiments thereof, it is to be understood that various modifications, alterations and adaptations may be made by those skilled in the art without departing from the spirit and scope of the invention.

[0021] As mentioned above, the motor vehicle occupant protection arrangement may be placed at other locations within the motor vehicle, such as around door openings, within a steering wheel, or within occupant seats. It may also be designed to have a mouth that only on one side is connected to a resilient material such as the sheathing. The other side may be connected to, in relation to the flexibility of the sheathing, rigid part of the motor vehicle.

[0022] The housing may not be entirely wedge-shaped, but if needed, deviate somewhat from that shape. 

1. A motor vehicle occupant impact protection arrangement (1) comprising an airbag device (2) within a housing (3), an airbag device launch trigger (4), triggering the launching of said airbag device (2) upon a motor vehicle impact, and a sheathing (5), such as a dashboard in an occupant compartment (6) of the motor vehicle (7), to which said housing (3) is connected, and behind which, in relation to the occupant, said airbag device (2) is located, characterised in that said sheathing (5) is having a mouth (8) through which said airbag device (2), guided by said housing (3), is launched into said occupant compartment (6), and in that said sheathing (5), after the launch of said airbag device (2), is adapted to essentially return to original state and to essentially close said mouth (8).
 2. A motor vehicle occupant impact protection arrangement (1) according to claim 1, wherein said mouth (8) is an integrated part of said sheathing (5).
 3. A motor vehicle occupant impact protection arrangement (1) according to any of the above claims, wherein said mouth (8) is an aperture in said sheathing (5).
 4. A motor vehicle occupant impact protection arrangement (1) according to any of the above claims, wherein said housing (3) is forming wedge-shaped sliding surfaces (9) for said airbag device (2), said surfaces (9) converging towards said mouth (8).
 5. A motor vehicle occupant impact protection arrangement (1) according to claim 4, wherein said housing (3), in the part connected to the sheathing (5), is adapted to form resilient jaws.
 6. A motor vehicle occupant impact protection arrangement (1) according to claim 5, wherein said housing (3) in combination with said sheathing (5) is forming a resilient part adapted to enable opening of said mouth (8) against spring action and essentially closing of said mouth (8).
 7. A motor vehicle occupant impact protection arrangement (1) according to any of the above claims, wherein said airbag device (2) is comprising an inflatable airbag (10), which, upon triggering, is adapted to, against spring action, pressing said mouth (8) to open, and to inflate in said occupant compartment (6).
 8. A motor vehicle occupant impact protection arrangement (1) according to any of the above claims, wherein said airbag device (2) is replaceable after fulfilling its purpose at a motor vehicle (7) impact.
 9. A motor vehicle occupant impact protection arrangement (1) according to claim 8, wherein said airbag device (2) is replaceable by admission at a point on said sheathing (5) essentially transversal to the direction of inflation of said airbag device (2).
 10. A motor vehicle occupant impact protection arrangement (1) according to claim 9, wherein said airbag device (2) is replaceable by admission at a point on said sheathing (5) reachable from a motor vehicle door opening (11). 